1. Field of the Invention
The present invention relates to a dust cover mounting structure for the front fork of a two-wheel vehicle or the like and for a shock absorber used for such vehicle.
2. Description of the Related Art
In the prior art as shown in FIG. 14 of the attached drawings, a front fork assembly 100 for a motorcycle holds a pair of front forks 102 at both ends of under bracket 101, and an upper bracket (not shown), axially supports a front wheel in a freely rotating manner on front forks 102 and pivotally supports a steering shaft 103 arranged at a center portion of the under bracket 101 and the upper bracket to a head pipe (not shown) of the vehicle body frame, thereby steering the front wheel.
The front fork 102 is structured so that a vehicle body inner tube 104 is slidably inserted into a wheel side outer tube 105, so that the inner tube 104 is held to the outer bracket 101 and the upper bracket. The inner tube 104 is structured so that an outer peripheral surface thereof is protected by an upper dust cover 106 and an under dust cover 107.
The upper dust cover 106 is supported by a supporting member 109 made of a synthetic resin on an upper surface of the under bracket 101 through a washer 108. The under dust cover 107 has a flange 111 attached to an upper opening of a cylindrical cover main body 110, as shown in FIGS. 14 to 16. The under dust cover 107 has a mounting bolt 114 inserted into a hole 112 of the flange 111 and hole 113 of the under bracket 101 and is secured to the under bracket 101 by means of a nut 115.
However, in the prior art described above, since the under dust cover 107 is fixed to the under bracket 101 by using a plurality of, for example, three mounting bolts 114, it is necessary to form the bolt holes 113 and 112 in the under bracket 101 and the flange 111 of the under dust cover 107. This makes the shape of the under bracket 101 and the under dust cover 107 intricate and hard to use. The assembly operation of the under dust cover 107 is therefore difficult.
Further, since the under dust cover 107 is attached to the under bracket 101 by a plurality of mounting bolts 114, the load of the under dust cover 107 is shifted to the mounting bolt 114 having the greatest fastening torque, so that concentricity is difficult to obtain with respect to the inner tube 104. Accordingly, a slant phenomenon occurs where the axis of the under dust cover 107 and an axis of the inner tube 104 are inclined so that the under dust cover 107 is slanted in a direction of arrow A in FIG. 14. The under dust cover 107 is brought into contact with the outer peripheral surface of the outer tube 105, creating risk of rubbing the outer peripheral surface and causing wear and damage.